Autohide dock hides forever in Vista...

Just installed OD+ in Vista. Started to set up my dock just like I had it in XP, essentially an autohiding non tabbed dock on the top of the screen. All I did was change its position and set it to autohide and immediately found that once the dock hides, it does not unhide on mouseover. I have to go back into the dock properties window to get the dock to reappear. Never had this problem before, any suggestions?